Whenever we use two or more computers simultaneously we need that much keyboard and mouses.
This can be avoided by using a software called MOUSE WITHOUT BORDER.
Try this it is a nice software.

Mouse Without Borders was designed for people who use many computers in the same room. For example, a laptop or tablet that you take to meetings might sit right alongside the desktop PC in your office.

Windows: If you use multiple computers at the same desk, it’s annoying to use multiple sets of mice and keyboards. Free app Mouse Without Borders lets you share your mouse and keyboard with other machines, and even drag and drop files between them.

We’ve talked about apps that do this before, Mouse Without Borders is even more powerful. Not only can you drag your mouse between monitors, but you can even copy and paste text between computers and drag files from one to the other. It’s Windows only — unlike its competitor Synergy — but if you run Windows exclusively, it’s a powerful, dead simple way to limit the number of mice on your desk. Check out the video above to see more.